Summary of work: The analysis of the NHANES-I twenty year follow-up has been submitted for publication. Additional variables were added to the analysis: weight gain from minimal-even weight (since age 18) to age of enrollment in the study and weight loss from maximal-even weight to age of enrollment. Data on women are of questionable validity since weights attained in association with pregnancies were not excluded. An analysis of the relation of Body Mass Index to all-cause mortality in the male component of the Baltimore Longitudinal Study of Aging will be undertaken in FY '98. The number of deaths in the female component remains too small to allow meaningful analysis at this time. In collaboration with the Applied Physiology Section, formulae have been developed for the composition of percent body fat from anthropometric measurements. These data have been obtained on BLSA participants since the study was initiated. We now have adequate body composition data from Dual Energy X-rayAbsorptiometry studies which allow derivation of formulae for percent fat computation based upon multi-variate prediction equations on men and women.